Control unit for automatic vacuum cleaners



Dec. 24, 1957 J. 'r. FERRARIS 2,817,414

CONTROL UNIT FOR AUTOMATIC VACUUM CLEANERS Filed March 25, 1954 5 Sheets-Sheet 1 T1. 1. M0.

INVENTOR Joy/v TFE'EEflE/J WXM' TORNEY Dec. 24, 1957 J. T. FERRARIS 2,317,414

CONTROL UNIT FOR AUTOMATIC VACUUM CLEANERS Filed March 25, 1954 3 Sheets-Sheet 2 INVENTOR JO/l/VTFEEEHE/J A OQNEY 1957 J. T. FERRARIS 2,817,414

CONTROL UNIT FOR AUTOMATIC VACUUM CLEANERS Filed March 25, 1954 3 Sheets-Sheet 3 T134.

,moa Q 5 70 54 3 2/0 24 Z406 Z3 E. y Tlczri 2 203 Zdfle 20/ p 2w 2445 IN V EN TOR. cfOl/A/ 7." fZBmz/J ATTU/P/VEY United States CONTROL UNIT FOR AUTOMATIC VACUUM CLEANERS John T. Ferraris, Stamford, Conn., assignor to Electrolux Corporation, Old Greenwich, Conn., a corporation of Delaware Application March 25, 1954, Serial No. 418,717 7 Claims. Cl. 183-37) atent v predetermined measurable variations in the air suction stream occurring during its continued useas a dust collecting device.

The present invention has as an object the prevention of any sudden unnecessary operation of the control unit such as may be occasioned by the accidental sealing of a dust collecting nozzle, a result which may be caused by ascrap of paper being sucked against the nozzle mouth or a casual contact of the open nozzle with a flat impervious floor surface.

Another object of this invention is to provide a control unit which effects a direct connection between an actuating power diaphragm and the source of pressure or vacuum available for its operation. This assures rapid and complete operation of the control apparatus and prevents any chattering or fluttering operation thereof.

"Other and further objects and advantages of this invention will become readily apparent upon reading the following description together with the accompanying drawings wherein:

Figure l is a front plan view of a tank type vacuum cleaner, showing the location of the new control unit in broken lines;

Figure 2 is a side view of a tank type cleaner, with portions of the outside casing broken away to show the location of the control unit more clearly;

Figure 3 is a top plan view of the cover and control unit removed from the cleaner, showing the cover in released position;

, Figure 4 is a sectional view taken on the line 4--4 of Fig. 3, showing some internal structural details of the control unit and power diaphragm;

. FigureS is a vertical section of the control unit taken on the line 5-5 of Fig. 4, showing one modification thereof; and

Figure 6 is a vertical section of a modified type of control unit taken on a line corresponding to that of Fig. 5, but showing a variation thereof utilizing a solid stem, thus necessitatingan additional pressure communicating tube.

It is a feature of this invention that the functioning of the cleaner in its dust disposal capacity is automatic, self-contained and after being once initiated by the establishment of predetermined changes in the operational characteristics of the air suction stream within the cleaner, the entire sequence of operations terminating, for example, in a visible or audible signal, in the opening of the cover, etc., is effected in a series of steps. Thus, with continued dust collection during the regular operation .of the cleaner, a pressure difference is gradually built up within the cleaner between the inside and the outside of the dust collecting bag, that is between the,

upstream and downstream sides thereof. This results in a continuous and progressively increasing force being exerted upon a pressure differential measuring or control diaphragm, the opposite sides of which are subjected to the different pressures built up on the outside and inside of the dust bag, the chamber on one side of the diaphragm being connected to an opening communicating behind the clean side of the dust bag, namely between the dust bag and the motor fan unit, the chamber on the other side of the diaphragm being connected. to an opening communicating ahead of the dirty side of the dust bag.

Then, upon the attainment of a predetermined value in the resultant force exerted upon the pressure differential diaphragm, motion is imparted to this diaphragm and at a predetermined distortion the diaphragm conditions means which sets into operation a series or sequence of pneumatic and mechanical steps, which sequence when once initiated culminates finally in the opening of the cleaner cover and/ or the deenergization of the motor fan unit.

In a preferred embodiment, the dilferential pressure or control diaphragm actuates means which in turn opens a valve for admitting suction from the motor fan unit to actuate a second or assist diaphragm which, operating through a series of linkages, (1) selectively positions a member which thereafter is in condition for subsequent operation and release of its associated restraining mechanisms; and (2) in timed relation therewith this second diaphragm substantially simultaneously, or thereafter, actuates means which releases a dust conveying inlet conduit from operative communication with its dust receptacle. Then, the conduit after a predetermined angular travel towards its fully released position in turn breaks a circuit cutting ofi the power supply to the motor fan unit.

Referring now more particularly to the drawings, vacuum cleaner housing 10, Fig. 2, is a hollow casing. It is appropriately supported on a pair of runners, 12. The suction or inlet portion of the casing 10 is provided with an inlet nozzle and wand together with a suitable conventional flexible hose (not shown), and connecting coupling fitted into a movable hose coupling assembly 15 which is anteriorly mounted by parallel linkage including front end assembly 16. Front assembly 16, as shown in Figs. 2 and 3, is hinged at 17 to base casting 199 and biased to open position by spring 18. Assembly 16 effects with casing 10 an airtight seal formed by rubber sealing ring member 19, cardboard disc 31, Fig. 2, of dust bag 30 and sealing ring 22 positioned in the bag insertion opening of front body ring 20. Tubular mem'- ber 21 of the hose coupling assembly 15 extends through the opening 32, Fig. 2, cut in cardboard disc 31 well into the dust collecting receptacle 30, and is sealed against disc 31 by rubber sealing ring 19. Switch button 10a on the upper front surface of cleaner housing 10 provides the on-and-oif manual control for the cleaner unit.

A perforated inner housing 23 is aflixed at one end. to front body ring 20 and is adapted for supporting dust bag 30 (of disposable paper or, if desired, cloth construction). This entire unit (inner housing 23, body ring 30, etc.) is slidably fitted within the open end of;

cleaner housing 10 and is atfixed thereto by suitable re-" taining screws. In the embodiment shown, the housing 23 is substantially rectangular in cross-section and is thus adapted to take a bag of substantially similar but slightly smaller cross-section 30, Fig. 2.

Dust bag 30, Fig. 2, comprises a dust receptacle of paper or similarly air-pervious, dust-impervious, -material ailixed at its mouth to the rear surface of a hard paper or cardboard disc 31, the latter being clamped between rubber Sealing ring 19 of hose coupling assembly ,1;

and the open end of'front body ring 20 with the aid of sealing ring 22. Cardboard disc 31 has a central opening 32 through which tubular member 21 is inserted in order to introduce the air and entrained dust directly into the interior of dust bag 30.

The entire inner surface of perforated inner housing or dust bag receiving compartment 23 is provided with apertures 27, Fig. 2, in order to permit free passage of suction air current therethrough and into chamber 40. The suction air current is induced by a motor fan unit 72, through which it passes to the rear of the vacuum cleaner housing 10.

The particular details of one embodiment for a cover releasing and restraining mechanism which is adapted to control alsothe movement of a latch bar 63 (Fig. 2) is clearly-shown in Figs. 2, 3, and 4. In these figures, a latch barrestraining and releasing pin 70, Figs. 2 and 3, is biased to latching position by spring 70a, Fig. 4, and, projectsthrough an opening formed in. baseplate, shelf 80. Pin 70 is adapted by, axial movement to. bewithdrawn from its latch bar restraining position (Fig. .2) toits latch ,bar' releasing position (Fig. 3) by the downward movement of actuating arm 75.

The above latch bar restraining and releasing. pin 70 for controlling operation of the dust bag ejector mechanism is moved from its normal position (shown in Fig, 2) to its withdrawn position (shown in 3) by the downward movement'of link 254 which actuates arm 75vto withdraw pin 70. Link 254 is attached at its lower end to a pneumatic means comprising a power diaphragm 250 the 'upper side of which is subjected to. atmospheric pressure and the underside to the pressure existing within a power diaphragm chamber 251. The withdrawal of pin 70 releases for clockwise rotation pin retaining finger 90a, Fig. 3, which, in the form of a lever arm fulcrumedon shaft 90b and affixed thereto to move as a unit, functions to prevent relatching of latch bar 63 by pin 70. The pin retaining finger 90a is spring biased'to effect this movement.

Thus the above-mentioned selective positioning of pin 70 results in the superpositioning of retaining finger 90a (Fig. 3) above pin 70 to retain the latter in releasing position outofthe pathof latch bar 63.

Assembly 16, is held closed by latch100, Figs. 2, 3, engaging keeper- 101; latch 100 being fulcrumed at 100a and biased to latching position by spring The cleaner housing 10 may be opened for inspection of the bagand. its contents without ejecting the dust bag by manually lifting the externally protruding end 1000 oflever 10.0, Figs. 1, 2 and 3, therebyv releasing the frontend assembly 16. Since pin 70 most likely will not. have been selectively positioned (withdrawn) to latch. bar releasing position, pin 70 will still restrain latch bar 63 and hence keep the bag ejector from discharging the dust bag.

It is to benoted thatpower diaphragm 250 in addition to triggering pin 70 and setting the mechanism for the subsequent release of ejector restraining latch bar 63 also releases, substantially simultaneously, the coverreleasing lever 100 by actuating arm 75, Figs. 3 and 4, formed as a part of latch release device fulcrumed at 75a thereby releasing cover 16.

The parallel linkage of the hose coupling assembly to the base member 199 is most clearly seen in Fig. 3. There, link 1'15 pivoted at1'16 to base casting 199 and at 117 to hose coupling assembly 15 forms one link in the parallel linkage while cover 16 fulcrumed at 17 to base casting 199 and at 118,to hose coupling assembly 15 forms the other link.

Button- 10a, Figs. 1 and 2, on the upper front surface of-housing 10 operates a circuit make and break switch of the conyentional toggle snap switch type.

"The chamber 251 on one side of power diaphragm 250 isoperatively connected to the high suction side of the vacuum cleaner, namely chamber 40, by conduit 255, the top chamber 220, valve 240, center opening a in casing 80, to the inner sealed chamber 40.

The pneumatic control system includes a control diaphragm 203 disposed in a control housing 201 and dividing the housing into a first chamber below the diaphragm and a second chamber above it. A spring 203a in the second chamber biases the diaphragm downwardly and the first chamber is connected through a flexible conduit 210 with the tubular member 21 which communicates with the upstream or dirt collecting sideof the-dust bag. Separated from housing 201 by a partition 202 is an assist housing 204 in which is located an assist diaphragm 270. A hollow valve stem 240a having a bore 240]; is slidably positioned in anopening in partition 202, is secured to assist diaphragm 270, and carries at its upper end a valve 240 which controls flow through a large aperture connecting the chamber 220 above assist diaphragm 270 with the space 40 within casing 10. The hollow stem 240a, formed with a restriction 240:: at: the upper end of bore 240b, establishes communication, between space 40 and the aforementioned second chamber in housing 201 above control diaphragm. 203. The chamber 220 in housing 204 above assist diaphragm 270, is connected to power diaphragm chamber 251, through a conduit 255, While the chamber below theassist-v diaphragm is open to atmosphere through openings 2.0211. A spring 240d urges valve 240 towards closed position.

As dirt accumulates within the dust bag, the resistance; to the flow of air therethrough increases, and hence the:

air pressure on the downstream side of the bag in cham,.

ber 40 gradually decreases, while the pressure on the Inasmuch as.

phragm 203 and the latter is communicated through con duit 210 to the chamber below the control diaphragm,

the diaphragm is caused to move upwardly against the resistance of spring 203a. As the pressure differencein-v creases, the diaphragm 203 continues to move until it contacts the lower end of valve stem 240a. Further movement lifts the stem and valve 240, thus suddenly connecting the chamber 220 above assist diaphragm 270] with the low pressure region in chamber 40. Inasmuch as the lower side of the assist diaphragm is subjected to atmospheric pressure, the assist diaphragm moves 'upquickly, thus fully opening valve 240 and assuring that the valve will remain open, even if there should be a decrease in the pressure difference acting on control diaphragm 203 which would cause the latter to move downwardly.

The opening of valve 240 connects power diaphragm chamber 251 directly with chamber 40 through a path comprising conduit 255 and chamber 220 which is freeof obstructions, such as the restriction 2400 in the bore 24% of valve stem 240a. This restriction is desirable so as todampen sudden fluctuations in pressure, as might result from suddenly sealing or unsealing the rug nozzle. It is not desirable for such fluctuations to operate the controls, and the presence of the restriction 240a assures that only changes of substantial duration, such as those resulting from accumulation of dirt in the bag, will cause the controls to operate. 7

As previously described, the applications of low pres sure to power diaphragm chamber 251, causespower diaphragm 250 and link 254 to move downwardly, thus pivoting arm 75 so as to withdraw pin 70 and to release lever from keeper 101.

With the opening of front end assembly 16, the discharge of the bag and the slowing downof the motor fan unit, atmospheric pressure is'reestablished on-both sides-of each of di aph-ragms 203 and 270which are returned to their original positions, under thebiasing action of'springs- 203a and 240d, respectively;

The electrical system for energizing the motor fan unit 72, Fig. 2, and the electrical controls are of the conventional form and hence need not be specifically described.

The variation of the control unit shown in Fig. 6 is somewhat similar to that of Fig. 5 except that a solid valve stem 2402 is used and conduit 225, Fig. 6 (indicated by broken lines in Fig. 3) together with flow restriction means 230 opening into chamber 40 on the clean side of the dust bag is used instead of hollow center bore 24% of Fig. 5. In either variation, the flow restriction means 230 or 24% functions to prevent surging and sudden movement of diaphragm 203 such as may be caused by the sudden sealing of a cleaning nozzle. A flexible rubber sealing ring 290 serves to effect a leak proof joint between unit 200 and the casing 80. When the unit shown in Fig. 5 is used, opening 230, Fig. 3, is sealed or omitted entirely.

It is to be understood that the specific embodiments herein described in considerable detail are merely illustrative of the invention which is to be limited in scope solely by the appended claims.

What I claim is:

1. In a vacuum cleaner, a casing, a dust separating member in said casing, means for producing flow of air through said casing and through said member therein, a control housing, a control diaphragm within said housing dividing the latter into a first chamber and a second chamber, conduit means for connecting said first chamber to the interior of said casing on one side of said member, conduit means for connecting said second chamber to the interior of said casing on the other side of said member, pneumatic means for controlling an operation of said cleaner, and valve means actuated by movement of said diaphragm for connecting said pneumatic means with said means for producing flow of air independently of said conduit means.

2. In a vacuum cleaner, a casing having an inlet opening, means in said casing for producing flow of air therethrough, a dust separating member in said casing between said inlet and said means, a control housing, a control diaphragm therein dividing said housing into a first chamber and a second chamber, conduit means for connecting said first chamber to the interior of said casing between said member and said inlet, conduit means for connecting said second chamber to the interior of said casing between said member and said means for producing flow, flow restricting means in the last mentioned conduit means for dampening the effect on said dia phragm of sudden pressure changes, pneumatic means for controlling an operation for said cleaner, and valve means actuated by movement of said diaphragm for connecting said penumatic means directly and independently of said last mentioned conduit with the interior of said casing between said member and means for producing flow.

3. In a vacuum cleaner, a casing, a dust separating member in said casing, means for producing flow of air through said casing and through said member therein, a control housing, a control diaphragm within said housing dividing the latter into a first chamber and a second chamber, conduit means for connecting said first chamber to the interior of said casing on the up stream side of said member, pneumatic means for controlling an operation of said cleaner, and a valve having a hollow stem for connecting said second chamber to the interior of said casing on the downstream side of said dust separating member, said stern being actuated by movement of said diaphragm for operating said valve to connect said pneumatic means with said means for producing flow of air independently of the passage through said hollow valve stem.

4. In a vacuum cleaner, a casing, a dust separating member in said casing, means for producing flow of air through said casing and through said member therein, a control housing, a control diaphragm within said housing dividing the latter into afirst chamber and a second chamber, conduit means for connecting said first chamber to the interior of said casing on the upstream side of said member, pneumatic means for controlling an operation of said cleaner, a valve having a hollow stern for connecting said second chamber to the interior of said casing on the downstream side of said dust separating member, and flow restricting means in said hollow stem for dampening the effect on said diaphragm of sudden pressure changes, said stem being actuated by movement of said diaphragm for operating said valve to connect said pneumatic means with said means for producing flow of air independently of the passage through said hollow stern and the flow restricting means therein.

5. In a vacuum cleaner, a casing, a dust separating member in said casing, means for producing flow of air through said casing and said member therein, a power diaphragm for controlling an operation of said cleaner, a control housing, an assist housing, a partition separating said housings, said partition being formed with an opening, a control diaphragm in said control housing, conduit means for connecting the interior of said control housing on one side of said control diaphragm to the space in said casing on the upstream side of said dust separating member, conduit means for connecting the interior of said control housing on the other side of said control diaphragm to the space in said casing on the other side of said member, flow restricting means in said last-mentioned conduit, said assist housing having an aperture communicating directly and independently of said last-mentioned conduit with the air flow producing means in said casing, means for communicating air pressure from said assist housing to said power diaphragm, an assist diaphragm in said assist housing, a stem connected to said assist diaphragm and extending through said opening in said partition so as to be displaced by motion of said control diaphragm,

and valve means carried by said stem for normally closingv said aperture and operable by displacement of said stem for establishing communication through said aperture directly between said air flow producing means and said assist housing for operating said power diaphragm.

6. In a vacuum cleaner, a casing, a dust separating member in said casing, means for producing flow of air through said casing and said member therein, a power diaphragm for controlling an operation of said cleaner, a control housing, an assist housing, a partition between said housings, said partition being formed with an opening, a control diaphragm in said control housing, conduit means for connecting the interior of said control housing on one side of said control diaphragm to the space in said casing on the upstream side of said dust separating member, said assist housing having an aperture communicating directly with the air fiow producing means in said casing, means for communicating air pressure from said assist housing to said power diaphragm, an assist diaphragm in said assist housing, a stem connected to said assist diaphragm and extending through said opening in said partition so as to be displaced by motion of said control diaphragm, an axial duct in said stern for connecting the interior of said control housing on the other side of said control diaphragm to the space in said casing on the other side of said dust separating member, flow restricting means in said duct, and valve means carried by said stem for normally closing said aperture and operable by displacement of said stem for establishing communication through said aperture directly between said air flow producing means and said assist housing and independently of said duct for operating said power diaphragm.

7. in a vacuum cleaner, a casing, a dust separating member in said casing, means for producing a flow of air through said casing and said member therein, a power diaphragm for controlling an operation of said cleaner, a

control "housing, anaa'ssist. housing, a partition between :saidhou'sings, said partition being formed withvan opening, a control diaphragm in said control housing-means for subjecting the opposite sides of said control diaphragm to the respective pressures on opposite sides of said dust separating'rnember, said assist housing having an aperture communicating directly Withthe air flow producing means in said casing, means for communicating air pressures from said assist housing to said power diaphragm, an assist diaphragm in said'assistthousing, a stern connected to said assist diaphragm and extending through said opening in said partition so as to be displaced by motion of displacementof said stern for establishing communication through said aperture directly between said air flow producing means and-said assist housing for operating said power diaphragm.

References Cited in the file of this patent UNITED STATES PATENTS 10 2,641,330 Lofgren et al. June 9, 1953 2,642,151 Borkoski June 16, 1953 -2,667;943 Beede Feb. 2,.1954 

